Cobalt nanoparticles embedded nitrogen doped carbon, preparation from alkali deprotonation assisted ZIF-67 and its electrocatalytic performance in oxygen evolution reaction

Abstract

The development of safe, cost-effective and efficient electrocatalyst is significant for oxygen evolution reaction (OER). Herein, cobalt nanoparticles embedded-nitrogen doped carbon composite (Co-NC) is prepared by pyrolysis of a Co based zeolitic imidazolate framework (ZIF-67) precursor, which is synthesized by KOH assisted deprotonation of 2-methylimidazole ligand and coordination with Co(Ac)2 in a safe ethanol medium. The alkali deprotonation and employment of Co(Ac)2 reactant obviously enhance the yield, phase purity and structural stability of the afforded ZIF-67 precursor (denoted as K-ZIF-67-Ac) and further the OER catalytic efficiency of the resultant Co-NC composite. The typical Co-NC catalyst prepared by carbonization of K-ZIF-67-Ac at 800 °C in N2 atmosphere, denoted as K-ZIF-67-Ac-800, displays obviously lower overpotential (350 mV) at current density of 50 mA cm−2, higher OER catalytic kinetics and robust durability over other ZIF-67 derived Co-NC catalysts. The current work paves a feasible avenue to prepare efficient Co-NC OER catalyst from alkali deprotonation assisted ZIF precursor.